Method for fabricating light emitting diode chip

Abstract

A method for fabricating an LED chip includes: providing a sapphire substrate with a SiO 2 pattern layer formed on the substrate; forming a lighting structure on the sapphire substrate with the SiO 2 pattern layer; forming grooves in the lighting structure to divide the lighting structure into a number of light emitting regions, the grooves extending to the sapphire substrate and revealing the SiO 2 pattern layer; removing the SiO 2 pattern layer and forming spaces between the lighting structure and the substrate; etching part of the light emitting regions, and then forming electrodes on the light emitting regions; and cutting the sapphire substrate along the grooves to obtain a plurality of LED chips.

1 . A method for fabricating an LED chip, comprising:
 providing a sapphire substrate with a SiO 2  pattern layer formed on the substrate;   forming a lighting structure on the sapphire substrate with the SiO 2  pattern layer;   forming grooves in the lighting structure to divide the lighting structure into a number of light emitting regions, the grooves extending to the sapphire substrate and revealing the SiO 2  pattern layer;   removing the SiO 2  pattern layer and forming spaces between the lighting structure and the substrate;   etching part of the light emitting regions, and then forming electrodes on the light emitting regions; and   cutting the sapphire substrate along the grooves to obtain a plurality of LED chips.   
     
     
         2 . The method for fabricating an LED chip of  claim 1 , wherein the SiO 2  pattern layer comprises a plurality of SiO 2  strips paralleled to each other. 
     
     
         3 . The method for fabricating an LED chip of  claim 1 , wherein the SiO 2  pattern layer comprises a plurality of SiO 2  blocks arranged as a grid structure. 
     
     
         4 . The method for fabricating an LED chip of  claim 2 , wherein the cross sections of the SiO 2  strips along the length direction of the strips are trapezoid-shaped. 
     
     
         5 . The method for fabricating an LED chip of  claim 1 , wherein the SiO 2  pattern layer is removed by BOE solution. 
     
     
         6 . The method for fabricating an LED chip of  claim 5 , wherein the BOE solution is a mixture of hydrofluoric acid (HF) and ammonium fluoride (NH 4 F). 
     
     
         7 . The method for fabricating an LED chip of  claim 1 , wherein the light emitting structure comprises an n-type GaN layer, a MQW layer and a p-type GaN layer formed subsequently in a direction away from the sapphire substrate. 
     
     
         8 . The method for fabricating an LED chip of  claim 7 , wherein an ITO transparent conductive layer is further formed on the p-type GaN layer before etching part of the light emitting regions. 
     
     
         9 . The method for fabricating an LED chip of  claim 7 , wherein part of the lighting regions are etched to expose part of the n-type GaN layer as an electrode supporting platform, and then a p-type GaN electrode and an n-type GaN electrode are formed on the p-type GaN layer and the exposed n-type GaN layer respectively. 
     
     
         10 . The method for fabricating an LED chip of  claim 1 , wherein material of the electrode is selected from a group consisting of Ti, Al, Ag, Ni, W, Cu, Pd, Cr, Au and alloy thereof. 
     
     
         11 . The method for fabricating an LED chip of  claim 1 , wherein the grooves are formed in the lighting structure by dry etching.